A crash dump is a file that captures the memory of a computer at the moment it crashes. This file helps developers and system administrators diagnose the cause of the crash by providing a snapshot of the system's state, including running processes and memory usage. When a system encounters a serious error, it may create a crash dump automatically. These dumps can be analyzed using debugging tools to identify issues in software or hardware, making them essential for improving system stability and performance. Common types of crash dumps include kernel memory dumps and full memory dumps.